1. Field of Invention
The invention relates to an antenna and a method of manufacturing the same, and, in particular, to a solid antenna and a method of manufacturing the same.
2. Related Art
The rapidly developed radio transmission has brought various products and technologies applied in the field of multi-band transmission, such that many new products have the performance of radio transmission to meet the consumer's requirement. The antenna is an important element for transmitting and receiving electromagnetic wave energy in the radio transmission system. If the antenna is lost, the radio transmission system cannot transmit and receive data. Thus, the antenna plays an indispensable role in the radio transmission system.
In the radio transmission system, the currently used frequency band specifications include IEEE 802.11, IEEE 802.15.1(bluetooth communication), and the like. IEEE 802.11 is further divided into the specifications of IEEE 802.11a, IEEE 802.11b and IEEE 802.11g. IEEE 802.11a is the specification corresponding to the frequency band of 5 GHz. IEEE 802.11b and IEEE 802.11g are the specifications corresponding to the frequency band of 2.4 GHz. IEEE 802.15.1 is also the specification corresponding to the frequency band of 2.4 GHz.
To meet the above-mentioned specifications, a solid antenna is often used. Referring to FIGS. 1A to 1E, the method of manufacturing the conventional solid antenna includes steps 1 to 8.
As shown in FIG. 1A, the first step is to provide a rectangular metal sheet 1 having long sides 11 and 11′ parallel to each other, and short sides 12 and 12′ parallel to each other.
As shown in FIG. 1B, the second step is to form a first slit 13 parallel to the short side 12 from the long side 11 of the rectangular metal sheet 1. Then, the third step is to form a second slit 14, which is parallel to the first slit 13 and has the length the same as that of the first slit 13, from the long side 11 of the rectangular metal sheet 1. A region formed between the first slit 13 and the second slit 14 is defined as a feeding portion 21. The fourth step is to form a third slit 15 connected with one end of the first slit 13 from the short side 12 of the rectangular metal sheet 1, and removes a rectangular metal sheet 16, which is a part of the rectangular metal sheet 1. The fifth step is to form a fourth slit 17 connected with one end of the second slit 14 from the other short side 12′ parallel to the short side 12 of the rectangular metal sheet 1, and removes another rectangular metal sheet 18, which is another part of the rectangular metal sheet 1.
As shown in FIG. 1C, a region formed between the short side 12 of the metal sheet and a virtual line distant from the short side 12 by a distance D is defined as a grounding portion 22, and the region exclusive of the grounding portion 22 and the feeding portion 21 is defined as a radiating portion 23.
As shown in FIG. 1D, the sixth step is to bend the feeding portion 21 along a direction parallel to the other long side 11′ by 90 degrees, and bends the grounding portion 22 along a direction parallel to the other short side 12′ by 90 degrees. Then, the seventh step is to place a supporting block F between a printed circuit board 24 and the radiating portion 23 to make the printed circuit board 24 in parallel to the radiating portion 23. Accordingly, the feeding portion 21 and the grounding portion 22 can contact the printed circuit board 24 firmly. Thus, it is possible to prevent the difficult bonding process due to the skew of the printed circuit board 24 relative to the feeding portion 21 and the grounding portion 22.
As shown in FIG. 1E, the eighth step is to electrically connect the feeding portion 21 and the grounding portion 22 with the printed circuit board 24 by way of bonding, and to take out the supporting block F to complete the steps of manufacturing the solid antenna.
However, the metal waste products, which include the rectangular metal sheets 16 and 18 and are removed when the solid antenna is manufactured, occupy 20 to 35% of the overall rectangular metal sheet 1, as shown in FIG. 1B. In other words, the effectively used region of the rectangular metal sheet 1 only occupies 65 to 80%, and the other portions are wasted, thereby increasing the material cost. In addition, the feeding portion 21 and the grounding portion 22 are electrically connected with the printed circuit board 24 only through one end 211 of the feeding portion 21 and one end 221 of the grounding portion 22, as shown in FIG. 1D. Because the contact surface area is small, the feeding portion 21 and the grounding portion 22 tend to separate from the printed circuit board 24 during the manufacturing processes or in the subsequent usage. Thus, the product quality is influenced.
Therefore, it is an important subject of the invention to provide a solid antenna with enhanced connection between the printed circuit board and each of the feeding portion and the grounding portion, a reduced ratio of the metal waste product to the overall metal sheet, and a simplified manufacturing method thereof.